Answer: a) (176.76,172.24), b) 0.976.
Step-by-step explanation:
Since we have given that
Mean height = 174.5 cm
Standard deviation = 6.9 cm
n = 50
we need to find the 98% confidence interval.
So, z = 2.326
(a) Construct a 98% confidence interval for the mean height of all college students.
![x\pm z\times \dfrac{\sigma}{\sqrt{n}}\\\\=(174.5\pm 2.326\times \dfrac{6.9}{\sqrt{50}})\\\\=(174.5+2.26,174.5-2.26)\\\\=(176.76,172.24)](https://tex.z-dn.net/?f=x%5Cpm%20z%5Ctimes%20%5Cdfrac%7B%5Csigma%7D%7B%5Csqrt%7Bn%7D%7D%5C%5C%5C%5C%3D%28174.5%5Cpm%202.326%5Ctimes%20%5Cdfrac%7B6.9%7D%7B%5Csqrt%7B50%7D%7D%29%5C%5C%5C%5C%3D%28174.5%2B2.26%2C174.5-2.26%29%5C%5C%5C%5C%3D%28176.76%2C172.24%29)
(b) What can we assert with 98% confidence about the possible size of our error if we estimate the mean height of all college students to be 174.5 centime- ters?
Error would be
![\dfrac{\sigma}{\sqrt{n}}\\\\=\dfrac{6.9}{\sqrt{50}}\\\\=0.976](https://tex.z-dn.net/?f=%5Cdfrac%7B%5Csigma%7D%7B%5Csqrt%7Bn%7D%7D%5C%5C%5C%5C%3D%5Cdfrac%7B6.9%7D%7B%5Csqrt%7B50%7D%7D%5C%5C%5C%5C%3D0.976)
Hence, a) (176.76,172.24), b) 0.976.
Answer:
If the total cost of the 4 necklaces was 18.40 then that means in order to find out how much she spent on pendents she needs to subtract the amount of beads from from the total cost so,
18.40-11.20=7.20
And cause she made 4 necklaces she is going to need to divide 7.20 by 4 to find out the cost of money that she had spent on each necklaces pendants.
7.20÷4=1.80
Meaning that she had spent $1.80 on each necklaces pendants